Green’s Dictionary of Slang

(Can./US) a mail-order catalogue.

1933		Buckner ‘Ranch Diction of the Texas Panhandle’ in AS VIII:1 32: wishbook. A mail-order catalogue.
1936		R.F. Adams Cowboy Lingo 206: The catalogue of a mail-order house was called a ‘wish book.’.
1971		Alberta Hist. Rev. Summer 25/1: That was when we would look at our ‘Wish Book’, the mail order catalogue, until it was out of date, and then tear the pages out in the ‘House of Parliament’ [OED].